Linear motors are used in a variety of applications, including automated positioning systems, robotics, hard drives, semiconductor manufacturing, and electronic assembly. A description of linear motor construction and operation is provided in U.S. Pat. No. 4,839,543, issued to Trilogy Systems Corporation., which is incorporated herein by reference. A position encoder system for positioning linear motors is described in U.S. Pat. No. 6,326,908, also issued to Trilogy Systems Corporation, and also incorporated herein by reference.
Shown in FIG. 1A is a top view, and shown in FIG. 1B is an end cross-sectional view, of a conventional glide assembly for mounting a linear motor. Linear motor coil assembly 1500, which may be a slotless or an iron core motor assembly, is affixed to a plate 1100 by way of screws inserted into a plurality of screw holes 1530. Plate 1100 serves to conduct heat away from assembly 1500 and also serves to mount bearing block assemblies 1000 using bolts inserted into bolt holes 1110. Bearing block assemblies 1000 comprise roller bearings 1032 that roll against bearing rails 1030. Bearing rails 1030 are secured to a base plate 1200 by bolts inserted into a plurality of bolt holes 1041. The base plate 1200 may be secured to a fixed structure with bolts inserted into a plurality of bolt holes 1201. Also secured to base plate 1200 by bolts inserted into a plurality of bolt holes 1401 is a magnet support structure 1400, which supports a linear array of magnets 1540. Mounted to the linear motor coil assembly 1500 is a connector assembly (not shown) which enables current to be coupled to the coils of the motor. Also not shown, are sensors for detecting the position of the motor as described in U.S. Pat. No. 6,326,908.
The conventional glide assembly construction shown in FIGS. 1A and 1B presents several disadvantages. First, the assembly occupies a large volume of space. Second, the cost of the numerous parts comprising the assembly can be expensive. Weight is also a disadvantage. A simpler, less costly, lighter assembly is desired.
Thus, there is a need for an invention that overcomes limitations of the prior art.